GEOLOGY AND HUMAN HEALTH 
  

A.  INTRODUCTION

       Medical Geology is an emerging discipline that examines links
       between geologic materials and processes and the occurrence
       of human and/or animal diseases.  It has long been recognized
       that the geologic environment can affect human health through
       acute toxicity (e.g., short-term exposure to high concentrations
       of toxic substances), but the recent focus has been on chronic
       (i.e., long-term) effects that the geologic environment can have
       on human health. 
                         

B.  SPATIAL CORRELATIONS

       Spatial correlations between human health problems and geology
       are used as evidence for cause and effect relationships; however,
       there are reasons why such correlations can be difficult to detect.

        1.  DIETARY HABITS 

        2.  CONTAMINATION

        3.  SOCIETAL MOBILITY

C.  STUDIES LINKING GEOLOGY TO HEALTH

        1.  HEART DISEASE

              a.  Ohio Study

              b.  Georgia Study  

        2.  STOMACH CANCER

              a.  Devon England

              b.  Northern Iran

D.  CONCLUSION

        Human health can be affected by long-term exposure to either
        an excess or a deficiency of certain chemicals in the geologic
        environment (the soil or groundwater). Therefore it is important
        to understand the influence that geology has on environmental
        chemistry (e.g.: rock type and soil radon levels).

        Two examples where the links between geology, environmental
        chemistry, and human health are well-established:
 

        1.  GOITER

             United States "Goiter Belt" (larger map)

 

        2.  FLUOROSIS

             Fluoride Belts  

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